Isolation plug tool and method

ABSTRACT

An isolation plug tool including a mandrel, an anchor assembly disposed on the mandrel, a seal assembly disposed on the mandrel having a seal, and a sleeve removably disposed radially outwardly of the seal.

BACKGROUND

In the resource recovery industry there is often need to isolate asection of borehole, casing or tubing from an adjacent section ofborehole, casing or tubing. There are many designs of isolation plugsavailable in the art but each has its benefits and detriments. Some ofthe detriments come with cost disadvantages that the industry wouldprefer to avoid. Accordingly, the art will well receive alternativeisolation plugs that provide solid function at reduced cost.

SUMMARY

An embodiment of an isolation plug tool including a mandrel, an anchorassembly disposed on the mandrel, a seal assembly disposed on themandrel having a seal, and a sleeve removably disposed radiallyoutwardly of the seal.

BRIEF DESCRIPTION OF THE DRAWINGS

The following descriptions should not be considered limiting in any way.With reference to the accompanying drawings, like elements are numberedalike:

FIG. 1 is a schematic cross section view of an isolation plug tool asdescribed herein in a run-in position;

FIG. 2 is the plug as illustrated in FIG. 1 in the set position; and

FIG. 3 is a schematic elevation view of a wellbore system within whichthe isolation plug tool is disposed.

DETAILED DESCRIPTION

A detailed description of one or more embodiments of the disclosedapparatus and method are presented herein by way of exemplification andnot limitation with reference to the Figures.

Referring to FIGS. 1 and 2, an isolation plug 10 is illustrated in arun-in and set position, respectively. The plug 10 may be run on slickline, electric wireline or coiled tubing. The plug 10 comprises amandrel 12 upon which an anchor assembly 14 and a seal assembly 16 aredisposed. Further, a sleeve 18 is disposed radially outwardly of theseal assembly 16 to protect and deflect seals 20 and 22 during run in.Finally, a trigger assembly 24 is positioned on the mandrel 12 as wellthat will allow hydrostatic fluid pressure to actuate the tool 10 upon aselected trigger event such as temperature, time, or pressure, forexample. Alternatively, the tool may be actuated hydraulically, ifdesired. The following discussion is applicable to hydrostatic orhydraulic actuation but for the source of pressure. Upon the exposure ofthe tool 10 to the trigger event, the trigger assembly 24 opens the tool10 to hydrostatic fluid pressure (or hydraulic pressure is applied) andports that pressure through pressure pathway 26. Pressure pathway 26 isfluidically connected to an anchor port 28 such that hydrostaticpressure may act upon a hydrostatic chamber 30 which urges piston 32toward slips 34. Movement of the piston 32 occurs only after thepressure in the hydrostatic chamber 30 is sufficient to place a loadupon the piston 32 greater than a release threshold for a release member36 such as a shear screw. Upon the member 36 releasing, the piston 30moves toward the slips 34 causing them to move radially outwardly as isdepicted in FIG. 2. This motion anchors the tool in the borehole, casingor other tubular as the case may be.

Once the anchor assembly 14 is set, the sleeve 18 may be removed fromthe tool 10 and simply moved partially uphole or withdrawn from the holeby placing a tensile load on a sleeve mount 38 to which the sleeve 18 isconnected. The sleeve mount and sleeve can be seen removed in FIG. 2.Upon removal of sleeve 18, the seals 20 and 22 are allowed to naturallyrebound radially outwardly. The degree to which these seals may reboundradially outwardly is greater than the radial capability of commoncement plugs because they are both deflected and protected during runin. The seals 20 and 22 themselves thus present no impediment to motionin the borehole during running as they would if not for the sleeve 18and may be constructed with a larger expanded diameter than would be thecase if they were run traditionally. In addition, the tool benefits froma slimmer deployment (running) diameter. In an embodiment, sleeve 18includes one or more openings 40 to prevent differential pressure beinggenerated across the sleeve 18, which helps avoid difficulty in removingthe sleeve 18 from the seals 20 and 22.

Seals 20 and/or 22 may be directional seals in embodiments. Asillustrated both seals 20 and 22 are directional and are opposed to oneanother. In this embodiment, pressure testing may be accomplished foreach seal from uphole thereof by utilizing a negative pressure test forthe downhole seal 22 and a positive pressure test for the uphole seal20.

The tool 10 provides an excellent plug for cement in that it anchorspositively, and seals in both directions so that cement will not leakpast the seal 20 nor may gas leak uphole past seal 22 into the cement.Gas contamination of the cement is avoided and accordingly greatercement integrity is achieved in this manner.

Referring to FIG. 3, a wellbore system 50 is illustrated comprising aborehole 52 in a formation 54. The system 50 as illustrated includes astring 56 having a tool 10 therein run on one of the conveyingstructures mentioned above (electric wireline, slick line, or coiledtubing). The conveying structure is identified with numeral 58. Finally,cement 60 is illustrated as optionally disposed upon the tool 10.

Set forth below are some embodiments of the foregoing disclosure:

Embodiment 1: An isolation plug tool including a mandrel, an anchorassembly disposed on the mandrel, a seal assembly disposed on themandrel having a seal, and a sleeve removably disposed radiallyoutwardly of the seal.

Embodiment 2: The isolation plug tool as in any previous embodiment,wherein the anchor assembly includes a slip displaceable to a setposition by a piston.

Embodiment 3: The isolation plug tool as in any previous embodiment,wherein the piston is displaceable by hydrostatic or applied hydraulicpressure.

Embodiment 4: The isolation plug tool as in any previous embodiment,wherein the tool further includes a trigger assembly.

Embodiment 5: The isolation plug tool as in any previous embodiment,wherein the trigger assembly is responsive to one or more oftemperature, pressure, and time.

Embodiment 6: The isolation plug tool as in any previous embodiment,wherein the seal is a directional seal.

Embodiment 7: The isolation plug tool as in any previous embodiment,wherein seal is a plurality of seals.

Embodiment 8: The isolation plug tool as in any previous embodiment,wherein the plurality of seals are oppositely directional.

Embodiment 9: The isolation plug tool as in any previous embodiment,wherein the sleeve during running compresses a diameter of the seal.

Embodiment 10: The isolation plug tool as in any previous embodiment,wherein the sleeve includes an opening to alleviate differentialpressure across the sleeve.

Embodiment 11: A method for isolating one portion of a wellbore from anadjacent portion of the wellbore including deploying a tool as in anyprevious embodiment into the wellbore, anchoring the tool in thewellbore, and removing the sleeve from the seal.

Embodiment 12: The method as in any previous embodiment, wherein theanchoring includes hydrostatically or hydraulically setting theanchoring assembly.

Embodiment 13: The method as in any previous embodiment, wherein theremoving is by applying tensile force to the sleeve.

Embodiment 14: The method as in any previous embodiment, furthercomprising depositing cement on the tool.

Embodiment 15: A wellbore including a borehole in a formation, a stringin the wellbore, and a tool as in any previous embodiment disposed inthe string.

Embodiment 16: The wellbore as in any previous embodiment, furtherincluding cement disposed on the tool and extending uphole of the tool

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the invention (especially in the context of thefollowing claims) are to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. Further, it should be noted that the terms “first,” “second,”and the like herein do not denote any order, quantity, or importance,but rather are used to distinguish one element from another. The terms“about”, “substantially” and “generally” are intended to include thedegree of error associated with measurement of the particular quantitybased upon the equipment available at the time of filing theapplication. For example, “about” and/or “substantially” and/or“generally” can include a range of ±8% or 5%, or 2% of a given value.

The teachings of the present disclosure may be used in a variety of welloperations. These operations may involve using one or more treatmentagents to treat a formation, the fluids resident in a formation, awellbore, and/or equipment in the wellbore, such as production tubing.The treatment agents may be in the form of liquids, gases, solids,semi-solids, and mixtures thereof. Illustrative treatment agentsinclude, but are not limited to, fracturing fluids, acids, steam, water,brine, anti-corrosion agents, cement, permeability modifiers, drillingmuds, emulsifiers, demulsifiers, tracers, flow improvers etc.Illustrative well operations include, but are not limited to, hydraulicfracturing, stimulation, tracer injection, cleaning, acidizing, steaminjection, water flooding, cementing, etc.

While the invention has been described with reference to an exemplaryembodiment or embodiments, it will be understood by those skilled in theart that various changes may be made and equivalents may be substitutedfor elements thereof without departing from the scope of the invention.In addition, many modifications may be made to adapt a particularsituation or material to the teachings of the invention withoutdeparting from the essential scope thereof Therefore, it is intendedthat the invention not be limited to the particular embodiment disclosedas the best mode contemplated for carrying out this invention, but thatthe invention will include all embodiments falling within the scope ofthe claims. Also, in the drawings and the description, there have beendisclosed exemplary embodiments of the invention and, although specificterms may have been employed, they are unless otherwise stated used in ageneric and descriptive sense only and not for purposes of limitation,the scope of the invention therefore not being so limited.

What is claimed is:
 1. An isolation plug tool comprising: a mandrel; an anchor assembly disposed on the mandrel; a seal assembly disposed on the mandrel having a seal; and a sleeve removably disposed radially outwardly of the seal.
 2. The isolation plug tool as claimed in claim 1 wherein the anchor assembly includes a slip displaceable to a set position by a piston.
 3. The isolation plug tool as claimed in claim 2 wherein the piston is displaceable by hydrostatic or applied hydraulic pressure.
 4. The isolation plug tool as claimed in claim 1 wherein the tool further includes a trigger assembly.
 5. The isolation plug tool as claimed in claim 4 wherein the trigger assembly is responsive to one or more of temperature, pressure, and time.
 6. The isolation plug tool as claimed in claim 1 wherein the seal is a directional seal.
 7. The isolation plug tool as claimed in claim 1 wherein seal is a plurality of seals.
 8. The isolation plug tool as claimed in claim 7 wherein the plurality of seals are oppositely directional.
 9. The isolation plug tool as claimed in claim 1 wherein the sleeve during running compresses a diameter of the seal.
 10. The isolation plug tool as claimed in claim 1 wherein the sleeve includes an opening to alleviate differential pressure across the sleeve.
 11. A method for isolating one portion of a wellbore from an adjacent portion of the wellbore comprising: deploying a tool as claimed in claim 1 into the wellbore; anchoring the tool in the wellbore; and removing the sleeve from the seal.
 12. The method as claimed in claim 11 wherein the anchoring includes hydrostatically or hydraulically setting the anchoring assembly.
 13. The method as claimed in claim 11 wherein the removing is by applying tensile force to the sleeve.
 14. The method as claimed in claim 11 further comprising depositing cement on the tool.
 15. A wellbore comprising: a borehole in a formation; a string in the wellbore; and a tool as claimed in claim 1 disposed in the string.
 16. The wellbore as claimed in claim 15 further including cement disposed on the tool and extending uphole of the tool. 